One that comes to mind for me: “Whatever doesn’t kill you makes you stronger” is not always true. Maybe even only half the time! Are there any phrases you tend to hear and shake your head at?
“Practice makes perfect.”
Let me tell you about my 7th grade all county band audition, where I showed up and skillfully played 40 measures of not what the sheet music said because I misread it and practiced what I misread.
“Practice” needs some kind of mechanism for feedback and correction, such as a coach or instructor.